Magnetic bar pole chuck



April 12, 1921.

F. L. SIMMONS MAGNETIC BAR POLE CHUCK Filed Oct. 6. 1920 3 Sheets-Sheetl1 b :ET E oA 1&\111.11 Q\KN v V N W NM mN Sw w n.. N RN il 1927. Apr 12F. l.. slMMoNs MAGNETIC BAR POLE CHUCK Filed Oct. 6. 1920 3 Sheets-Sheet2 Hmm. mmmmwmmmw 1,624,076 Apnl 12,1921. F'LSIMMONS MAGNETIC BAR POLECHUCK Filed Oct. 6, 1920 I5 SheetSl-Shee: 3

t J 2g' el 4 ,el if gg I I l l I s u l I I the bridge'inember.

Patented Apr. 12, 1927.

nieuwe UNITED STATES PATENT carica.

FRANK LEROY SILIIMONS,A OF WOONSOGKET, RHODE ISLAND, ASSIGNOE T0 THE Tm-PEIRCE MANUFACTURING COMPANY, OF WOONSOCKET, RHODE ISLAND, .A OOR-PORATION OF RHODE ISLAND.

intensifie Ben. rom: CHUCK.

Application md catcher e, 192e. serial reclaim.

rlhis invention relates broadly to magnetic chucks and more specially toconstructions for concentrating and localizing the niagnetic forces.

The principal object of the present invention is to provide a magneticchuck with a plurality of longitudinally extending face plate pole,pieces supported upon and energized b a plurality of unit coil corepieces.

Another object of the present invention is a magnetic chuck having aplurality of longitudinally extending ace plate pole pieces each ofwhich are supported upon a plurality of unit coil core po pieces, withall the core pieces under a single face plate pole piece Wound toproduce the saine niagnetic signs when energized by 'a vsuitable lelectrical current.

A further and important object of the present invention is a magneticchuck having a plurality' of face plate pole pieces extending above thesup orting area of the face plate with the holding faces of the polepieces disposed to hold Work for edge grindmg.

Another object of the present invention is a magnetic chuck providedwith a face plate adapted to support Work against grinding or machineforces and magnetic poles having Work faces singularly disposed to thesup orting face whereby Work is magliet-` ical y held against one faceand supported against another face. c

A still further object of the present invention is a magnetic chuckprovided with a plurality of face plate polepieces having verticalextensions which are provided with vertical holding faces whereby Worlrmay be supported edgewise on the magnetic A still further object ci 4thepre invention is a magnetic chuck having i face plate Coniprisingfa'frame with a ge member across said frame and with tie pieces extendingfrom the sidesof said trarne to A still further object of'tlie presentinvention is a magnetic chuck having a traine provided with a bridgemember extending longitudinally thereof, with` individual coil carryingpole pieces directly beneath each face plete pole piece, with the corepieces nsupported on the base of a suitable housing, and having tiemembers extendinfv across the face plate frame and certain o the polepieces to provide a' rigid structure, 55

`A still further object of the present-'iw vention is an article ofmanufacture comprising a face plate for a magnetic chuck having aplurality ot pole pieces extending from the supporting surface of theface plate with a o0 face plate frame surrounding the pole pieces, andmagnetically separatedtherefrom, and tie members ot non-magneticmaterial yextending through said pole pieces 'and said frame.,

Other and further objects of the present invention will in part beobvious and will in part be pointed out hereinafter in the specificationfollowing :by reference to the accompanying dravving( forming a part 'zothereof and in which parts are desig- 'nateol by like charactersthroughout the several ieures.

Realizing that the present invention may be embodied in constructionsother than those specically shovvii and described, l de-l sire that thedisclosure herewith shall be considered as illustrative and. not in the.limiting sense.

Figure l is an elevational frontview of Agg a chuck embodyingthe presentinvention; Figure 2 is a plan View' otono form of face plate of a chucklembodying the present invention;

figure 3 is an end sectional view through 35 h the chuck illustrated inFigures fl and 2; *Figure 4 illustrates the invention embodied in theface plate having Work faces inclined to vertical;

Figure 5 is a plan view of another embodi- 9G K.

ment of the same invention; Figure 6` is a sectional view on line-f--Get' Figure 5;

. Figur@ 'l' is a detail View illustratingonemlf. y method ot mountingwork on the face plateJ--Fl f The most common type of magnetic chuckscomprises a magnetic chuck having afrec-4 tangular body portion with aplurality of `transversely extending face late pole pieces,v f Wheresuch chucks are utilized for holding lli work for vedge treatment suchas milling or grinding it has been customary to ursuc one of twomethods. One method being to support the work edgewise on the face plateby means of suitable parallels and rely upon magnetic holding forcesexerted on the supporting edge of the work to hold the work while it isbeing operated upon. In view of the fact that the edge of the majorityof work which requires edge treatment is thin the path of the magneticforces is very limited and 'the result, therefore, is that the holdingpower is often insuflicient. The second method comprises the utilizationof magnetizable auxiliary parallels or the like which set on the workface of the chuck and hold the work in position by means of mavneticforces transmitted through such auxiliary fixtures. rldhis method ismore satisfactory than the first but has disadvantage in that theauxiliary pieces are movable over the face plate and for certainaccurate work 1t is desirable that the parts shall be retained rigidlyas set.

rfhe present invention overcomes the difiiculties of the known art byproviding a magnetic chuck having face plate pole pieces arranged tocarry the magnetism above the supporting surface of the face plate andto concentrate the magnetism in a zone or plane angularly disposed tothe supporting sur face, preferably at right angles thereto, althoughother angles may b e utilized as deaired. ln this construction the partsare very rigidly and solidly arranged with core pole pieces setting onthe base of the housing and directly beneath the face plate pole piecesso that the shocks due to grinding or cutting tools is directlysupported by metal to metal Contact through to the base of the machinebed and the holding forces being singularly disposed to the supportingsurface provides a construction wherein work is very rigidly andsecurely held. Furthermore, the construction of the pole pieces is suchthat the magnetic forces are concentrated within a relatively smallrestricted area so that great holding power per unit of surface area 1sprovided. By providing a plurality of core pole pieces having bases, forcompleting the circuit of the magnetic lines of force, constructed toContact one with another a large area is provided for the magnetic:forces so that there is no appreciable leakage of the magnetic forcesto the housing and these forces are therefore concentrated over the facelate.

Referring to the drawings and more especially to Figures l to 3.inclusive, which illustrate one forni of the invention, theiion-rnagrietized housing l. preferably coinprises an open ybox adaptedto receive and support a plurality of cores 2 having bases t and corepole pieces 5. Thesecores are set upon brass or other non-magnetic metalLezama plates 6, and are held in position by nonmagnetic metal machinescrews 7. These core pole pieces comprise longitudinally extendingrounded end parallel plates which carry individual coils 8. Preferablythere are two groups of rowsl of cores and their respective coils asindicated in Figures 2 and 3. These coils may be connected in variousways but preferably are connected in two groups in such manner that thegroups may either be utilized in a series cir cuit or a. parallelcircuit, whereby the chuck may be adapted for 1l() volts or 220 volts,as the user may' desire. The terminals for the coil circuits may enter asuitable terminal box 9 to which the electrical current may be led bysuitable connectors. Preferably the upper edges of the housing and theupper ends of the core pole pieces when in position in the housing areall arranged in a common plane.

A suitable face plate. having the under surface thereof preferablyarranged to lie in a single (plane, is adapted to tit over the housingan core pole pieces and be energized thereby as will hereinafter beexplained. Preferably the face plate comprises a non-magnetized frame 10which is substantially rectangular in form and referably is providedthrough the longitudinal middle thereof with an integral rib or bridge1l. Z-shaped pole pieces 12 are arranged over one set of core polepieces and L-shaped pole pieces 14 are arranged adjacent the Z shapedpole pieces with the L-shaped pole pieces directly over and in contactwith the other set of core pole pieces. The upper ends of the L-shapedpole pieces extend over one of the arms of the Z-shaped pole pieces andterminate in the same plane as the side of the Z-shaped arms. Thisprovides work faces on the pole pieces which are substantially at rightangles to the supporting face of the face plate. Preferablynon-magnetizable washers l5 such as brass or the like are mountedbetween the pole pieces adjacent the extensions thereof, andnonmagnetizable machine screws 16 extend through the pole pieces and thewashers and bind the parts securely together. The space between the polepieces and the frame and also between the pole pieces and the bridge isfilled with babbitt metal or the like which is non-magnetizable andwhich tends to expand on cooling so that the parts will be securelyembedded therein and will be substantially waterproof. In order tofurther secure rigidity in the face plate the pole pieces of the framepreferably are drilled and non-macnetizable material such as brass, orthe like. dowel pins 17 are driven through the front frame and the frontgroup A of the pole pieces; while rear dowel pins 18 of the samecharacter are driven through holes bored through the'rear frame and therear group B of the pole pieces. [n the construction shown in Figures l,2, and 3a single face plate ole piece is provided for eac core polepiece and these face plate ole pieces are arranged in groups separated vtransverse lines of non-magnetic material. Transversely extending crossybrace screws 19 extend through openings drilled from the back bar ofthe frame through the bridge 11 through both groups A and B of the polepieces and are screw threaded into the front bar of the frame,Preferably these cross brace screws extend between the ends of thegroups of pole pieces, thereby providing a cross support member at theend of each pole piece gnjup. This pro-4 vides an exceedinglyrig1d,""firm, construction.

' Referring to Figure 2 it will be noted that the core pole pieces whenenergized by suitable current are arranged to be polarized inalternationso that alternate core pieces are of opposite magnetic signsthereby correspondingly energizing the face plate pole pieces.

As shown in Figuree the face plate pole pieces may be inclined atdegrees other than 90 degrees dependent upon the type of work for whichthe chuck is adapted.

In Figures 5 and 6 a slightly different embodiment of the resentinvention is il lustrated and wherein the cores 20 are arranged withbases extending the full Width of the chuck and the ends of the corepieces are machined and ahutted tightly together so that a complete basefloor .21 is provided through which all of the magnetic return forcesare adapted to be conveyed. In the embodiment illustrated in Fi ure 5theface plate pole pieces 22 and the acevplate pole pieces 24 extend thefull length of the chuck and veach pole piece is in contact with aplurality of core pole pieces of the same magnetic sign. The magneticfields in this type ofchuck comprises the base field and tielongitudinally extending face plate field with a plurality ofindividually energized posts, comprising core poles, extending betweentwo fields and forming the magnetic path between the fields; Thisvprovides an exceedingly strong holding force over the work face of thechuck. As illustrated in Figure 6, the magnetic lines C from 'li of theL-shaped pole piece trave work and returns throu h two face zshaped polepieces with the maj the lines of force returning through lne tical faceportions. This tends to hold work very tightly against.the work face.

Preferably supporting blocks 25 (EF 3 and 4) are provided with ribs 26'which form pivotsyon which the Work 27 is adapt ed to set. Also it isdesirable to provide rooves 28 adjacent the Work face and suitalile rods29 (Fig. 7) may be provided in claims the Words vertical and horizontalv are utilized more particularly as convenient designations for therelation of the parts,

and not particularly with Areference to the actual dimensions Vinreference to the surface of the earth; it being clearly obvious that thepresent chuck could be used on one side as Well as the base.

Having thus described my invention what I claim is:

l. A magnetic chuck comprising a face plate having a horizontalsupporting face, vertically extending pole pieceshaving side holdingfaces angularly disposed to said supporting face, and non-magneticmaterial between said pole pieces, one of said poles having a sidewiseextension extending across another pole and terminating in the sameplane as the other said pole to form said holding t'aceP 2A magneticchuck .comprising groups of core pieces, .2-shaped face plate polepieces vertically arranged and adapted to be energized by one group ofcore pieces, and L-shaped face plate pole pieces also verticallyarranged and adapted to he energized by the other group of core pieces.

3. A magnetic chuck comprising groups of core pieces, a series ci'Z-shaped face plate pole pieces vertically arranged and adapted to beenergized hy one group of core pieces, and a series of L-shaped faceplate pole pieces also vertically arranged and adapted vto be energizedhy the other group of core pieces, said poleI pieces being arranged toconstitute groups of pole pieces` ing operative faces located in thesame plana said' plane being substantially perpendicular to saidhorizontal surface and the operative face of one pole piece'being higherthan the operativel face of the other pole piece.

5. A magnetic chuck comprising in comhination a face plate having ahorizontal supporting surface, a l'uraltyof face plate pole pieceshaving ho ding faces extending vertically from said supporting surface,lthe face of one pole piece being nearer said horivertically from saidsupporting surface, the

face of one pole piece being nearer said horizontal surface than theface of another of said pole pieces, a Work rest positioned on saidhorizontal supporting surface adjacent said pole pieces, andelectromagnetic means to polarize said pole pieces.

FRANK LEROY SIMMozis.

